In recent years, rapid development of the nanotechnology, information technology and display technology has led to the ubiquitous age where people have access to information at anytime and anywhere. Accordingly, a need for mobile information electronic devices easy to carry with mobility has been increased. A need for flexible information electronic devices, which are freely deformed, flexible, lightweight, and easy to carry, as information devices for realizing the ubiquitous age has grown.
Most of the flexible information electronic devices represented by a flexible display, a flexible transistor, a flexible touch panel, and a flexible solar cell use a flexible transparent electrode as an electrode to control a current or light.
The flexible transparent electrode is an electrode formed on a flexible substrate, and has a high conductivity, a high transmittance in a visible region, and a high flexibility, and, thus, it can be applied to an electrode of a flexible information electronic device.
At present, ITO (indium tin oxide) has been mainly used as a transparent electrode. However, the ITO is expensive and fragile. Therefore, there is a limit to application of the ITO to flexible devices.
At present, various transparent conductive materials, such as graphene, carbon nanotube, and metal nanomaterial, are known as a material applicable to the flexible transparent electrode. By way of example, Korean Patent Publication No. 2013-0006868 describes a graphene substrate, and a transparent electrode and a transistor comprising the same.
However, polymer materials, such as PDMS (polydimethylsiloxane), PET (polyethylene terephthalate), and PAN (polyacrylonitrile), applicable to a substrate of the flexible transparent electrode have a strong hydrophobicity on their surfaces. Therefore, the transparent conductive material, which mainly has hydrophilicity, is not readily attached to the substrate. Accordingly, even if the substrate has flexibility, the transparent conductive material formed on the substrate is not stably attached to the substrate but easily separated therefrom. Thus, it has been difficult to achieve extensive commercialization of the flexible transparent electrode. In order to solve such a problem, plasma, a chemical vapor deposition method, LBL (layer by layer), and a surfactant have been used. However, these means may deteriorate elasticity of the substrate or cannot sustain their effects, and, thus, cannot fundamentally solve the problem.
The present disclosure can provide a transparent electrode and a method for manufacturing the transparent electrode in which a self-assembled monolayer is formed on a transparent substrate to enhance hydrophilicity of the transparent substrate, a metal nanowire layer is formed on the transparent substrate by using the hydrophilicity to have electrical conductivity, and a graphene oxide layer is formed on the metal nanowire layer to stabilize the metal nanowire layer.
However, problems to be solved by the present disclosure are not limited to the above-described problems. Although not described herein, other problems to be solved by the present disclosure can be clearly understood by those skilled in the art from the following descriptions.